The microstrain characteristics of continuously reinforced tungsten-copper composites have been studied as a function of volume fraction of fibers and prestrain. In the unstrained condition, the dislocation friction stress of all of the specimens studied had a value of approximately 0.28 kgf/mm2 (400 psi). The initial microyield stress, however, was dependent on the volume fraction of fibers, and a linear relationship was observed. Both the friction stress and microyield stress were prestrain dependent. The rate of increase of both of these quantities was dependent on the volume fraction of fibers. The results are discussed qualitatively in terms of high dislocation density regions in the copper matrix surrounding the fibers, which arise from stresses in the matrix as a result of the differential contraction between the tungsten and copper during fabrication.